Ronny Deila claims his Celtic squad are laughing their way to a potential treble.

The Scottish League Cup holders are eight points ahead of Aberdeen at the top of the Scottish Premiership and, with six games remaining, on course for their fourth successive title.

The next step towards a clean sweep in the Norwegian's first season as Hoops boss is Sunday's William Hill Scottish Cup semi-final against Inverness at Hampden Park and Deila insists the feel-good factor at the club is increasing by the week.

"I think there has been a very good atmosphere here for a long, long time and it is getting better and better," he said.

"People loosen up more when we know each other better and we are having a lot of fun here.

"One of the most important things needed to create and get better is to laugh a lot and enjoy life and I think that is something the players are doing. The togetherness is very good.

"But we know the moments to be very dedicated and to be focused when we train."

Deila, who will be without suspended striker Anthony Stokes and cup-tied midfield duo Stuart Armstrong and Gary Mackay-Steven, only has to look back to last Saturday to remind himself of the potential problems Premiership rivals Inverness could cause this weekend.

The teams fought out a scrappy 1-1 draw in the Highlands in their third league meeting this season, both sides having a previous win apiece under their belt.

The former Stromsgodset boss is hoping the brand new surface at Hampden Park, laid before the Hoops beat Dundee United in the League Cup final in March, will make for a better spectacle.

He said: "Inverness are a good team. They are well organised and they have a good spirit.

"Both teams want to play football so I think it will be a better match to watch than it was last time because I don't think there were more than four chances in 90 minutes.

"Hopefully there will be some more passing, better passing and more chances."

Striker Leigh Griffiths scored the goal against Caley but was left on the bench against Kilmarnock at Celtic Park in midweek, only to come on just before the hour mark at 1-1 and fire in a hat-trick to, ultimately, secure a comfortable win for the home side.

Deila praised the former Wolves player for his improvement under him this season but insists no one at Celtic Park can rest on their laurels.

"I see a lot of potential in all of the players but the difference between a good and not so good player is how good they are at learning and taking in new knowledge," he said.

"Leigh wanted to make a change and he has got his reward. I think you can see a lot of players have done the same.

"Virgil van Dijk is taking steps and Jason Denayer, Emilio Izaguirre is getting better. A lot of the players are into understanding and learning.

"What you did last night is not good enough tomorrow. You have to always be alert and learn new things and learn from experiences.

"And if you are in that way of thinking, you will always be ahead of your opponent."